Design of a new steerable in-pipe inspection robot and its robust control in presence of pipeline flow

Abstract

Robust multivariable control of an in-pipe inspection robot with variable pitch rate is performed in this paper which moves through the pipelines while fluid is flowing. Most of the traditional inpipe robots have two challenges which make difficulty for investigating the pipe line. The necessity of blocking the flow and difficulty toward bypassing the probable obstacles in the pipes. Here a new mechanism of inpipe robot is proposed which can bypass the obstacles as a result of its mechanism modification and also is able to work in presence of flow by the aid of its designed robust controlled. To meet this goal, the proper mechanism is designed and its related model is derived. Afterwards a nonlinear robust controller is designed and implemented on the proposed robot based on Sliding Mode Control (SMC). The efficiency of the designed robot for bypassing the obstacles and also the robustness of its corresponding controller in presence of flow are investigated by the aid of MATLAB simulation. These simulations are validated by modeling the system in ADAMS and comparing the response of the proposed SMC and Feedback Linearization (FL). It is proved that the designed robot is able to move with controllable velocity through full pipelines while the designed controller can successfully cancel the fluid flow disturbances with a good accuracy of order 10-2.